The second part of the Qatar '96 documentary, which was first broadcast on Al Jazeera on Sunday, revealed the involvement of Sheikh Hamad, who at the time was crown prince of Bahrain, in attempting to overthrow the Qatari government 21 years ago.

The investigation provided evidence of the involvement of Saudi Arabia, the United Arab Emirates (UAE), and Bahrain in supporting the failed coup d'etat.

Fahd al-Maliki, a prominent leader of the coup attempt, said Bahrains' Sheikh Hamad personally financed a series of sabotage operations and bombings in the Qatari capital. This was done under the pretence of an opposition front against then-emir Sheikh Hamad bin Khalifa Al Thani, father of Qatar's current emir.

Maliki, who fled to the UAE after the failed coup, said he received $265,000 from Sheikh Hamad in return for targeting government institutions, including the immigration department headquarters.

The attack was thwarted when the bomb failed to detonate and authorities found the explosive device in October 1996.

Maliki confirmed he personally contacted Reuters news agency and claimed responsibility for the bombing attempt on behalf of an organisation calling itself The Restoration of Legitimacy.

US confirmation

Then-US ambassador to Qatar, Patrick Thiers, said the intentions of those nations began to become clear after the failed coup attempt. The countries supporting the putsch were trying oust Sheikh Khalifa because they found Qatar's independent foreign policy unacceptable, according to Thiers.

The investigation described the extent of support provided to fugitives from Qatar and those involved in the failed coup attempt in February 1996, showing for the first time images of UAE and Bahraini passports granted to members of the Qatari military and coup leaders.

Retired Brigadier Shaheen al-Sulaiti, who was a senior member of the Qatari intelligence service, said Qatar's security services collected evidence implicating the three countries in the failed coup.

Sulaiti, who was one of the supervisors of the police investigation, said there was intensive communication between Qatari authorities and senior leaders in both the UAE and Saudi Arabia, which led to the extradition of a number of those involved.

Intensive communication

According to the investigation, in late 1997 Saudi Arabia handed over to Qatar one of the most prominent leaders of the attempted coup, Jaber Hamad al-Marri, who described the details of his extradition. Marri said he was subjected to torture and insults during the handover by Saudi security forces.

Maliki described the details of his escape from UAE security forces who tried to arrest him and hand him over to Qatar. He said he fled to Yemen before being handed over by authorities there to Doha in mid-1998.

According to Sulaiti, the coup attempt was considered over in 1996 with the arrest of coup leader Hamad bin Jassim bin Hamad Al Thani, who fled to Syria and was arrested in a security operation at Beirut airport.

Hamad, the then-police chief and cousin of the former emir, was taken by plane to Doha.

The coup attempt remained active in the Qatari courts, where various sentences were issued, including the execution of a number of coup leaders.

Amnesty granted

In May 2010, the late Saudi king Abdullah bin Abdul Aziz asked Qatar's emir to pardon 21 Saudi detainees involved in the coup and who were arrested by Qatari authorities. Doha agreed to the request.